The invention discloses a pre-installed direct-buried pipeline cable which comprises a collecting case. A fixed box is arranged in the bottom of the collecting case, a dampproof unit is arranged in the fixed box, a support frame is fixed to the upper end of the fixed box, a rotating roller is arranged on the support frame, two sides of the rotating roller are rotatably connected to the support frame, a crank is arranged on one side of the support frame, one end of the crank penetrates the support frame to be fixed to one end of the rotating roller, one connecting pipe is connected to one side of the collecting case, an installation plate is fixed to one side of the connecting pipe, a through hole is formed in the installation plate and is communicated with the connecting pipe, the connecting pipe and the installation plate are in one group, the other group is movably installed on the other side of a modified group, and the two groups are fixed through bolts. Through combination of the dampproof unit, the rotating roller, the crank and the connecting pipe, length of the pipeline cable is adjusted; meanwhile, convenience in disassembly and installation is achieved, dampproofness is realized, and the pre-installed direct-buried pipeline cable is suitable for promotion.